Propellent powder



Patented June 26, 1934 UNITED STATES PROPELLENT POWDER George C. Hale, Dover, N. J.

No Drawing. Application January 5, 1932, Serial No. 584,908

9 Claims.

(Granted under the act of March 3, 1883, as

amended April 30, 1928; 370 0. G. 757) The invention described herein may bemanufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon. This invention relates to propellent powder.

In the manufacture of modern propellent powders it is customary to add a non-volatile colloiding agent to the basic nitrocellulose composition in order that the volatile solvent, commonly ether alcohol, can be almost completely removed and the powder grains yet retain the desired degree of plasticity or compressibility. It is desirable that this colloiding agent which remains in the powder exercise colloiding action on nitrocellulose of high nitrogen content as well as that of low nitrogen content, since in many compositions a blend of lots of nitrocellulose having different nitrogen contents is used. The degree of solubility of highly nitrated nitrocellulose, 13.0-13.5% nitrogen, and nitrocellulose of lower nitrogen content, 12.0-12.75% nitgrogen, varies Widely with most of the common solvents used in powder manufacture and hence the colloiding agent which exercises gelatinizing or solvent action on these different nitrocelluloses is highly to be desired.

In the double base powders composed of nitrocellulose and nitroglycerine, the latter exercises such colloiding action to an excellent degree but nitrogylcerine has not proved an altogether satisfactory constituent of propellent powders which are required to be flashless as well as smokeless, non-hygroscopic and non-volatile.

I have found as a result of experiment that the nitroderivatives of ethylbenzene are excellent colloiding agents for nitrocellulose. They have a gelatinizing or colloiding action for nitrocellulose of any nitrogen content ordinarily used in the manufacture of smokeless powder. The mono and dinitrocompoundsare liquid at ordinary atmospheric temperatures and the trinitrocompound having a melting point of approximately 37 C. can easily be liquefied at ordinary temperatures by merely adding a relatively small amount 5 of the mono or dinitroderivatives. These compounds, therefore, lend themselves to use as colloiding agents for nitrocellulose and the fact that thediand trinitrocompounds contain a fairly high percentage of nitrogen, theoretically 14.3% and 17.4% respectively, they detract less from the ballistic potential of the powder than if inert colloiding agents were used. As a matter of fact as much as 27% 0d? trinitroethylbenzene has been used in propellent powder compositions to provide fiashless, non-volatile, non-hygroscopic properties to the powder without detracting sufficiently from the potential of the composition as to seriously impair the ballistic properties of the powder. The mono and dinitrocompounds having lower 50 nitrogen content than the trinitroderivative canreduction in the ballistic potential of a basic nitrocellulose composition but 5 to 10% of the lower nitrocompounds are sufficient to provide suflicient plasticity to the finished powder and also the desirable properties of reduced volatility and hygroscopicity.

Powders prepared for the m/m gun and containing 20% of trinitroethylbenzene and dinitroethylbenzene respectively showed a moisture absorption of only .83% and .82% respectively when conditioned in an atmosphere containing 90% relative humidity at a temperature of 30 C. This proves the effectiveness of these materials in reducing the hygroscopicity of nitrocellulose powders, since the latter of the same granulation and exposed to the same conditions will absorb above 2.5% moisture. The difierence here is an important consideration in the use of propellent powders.

This invention, therefore, covers the use of the nitroderivatives of ethylbenzene as colloiding agents for nitrocellulose and constituents of propellent powders containing nitrocellulose, it being understood that the compounds may be used separately or in admixture with each other or in admixture with the other common constituents of propellent powders.

I claim:

1. A propellent powder consisting of nitrocellulose and a mixture of dinitroethylbenzene and trinitroethylbenzene 20 to 27 per cent.

2. A propellent powder consisting of nitrocellulose and trinitroethylbenzene 20 to 2'7 per cent.

3. A process of colloiding nitrocellulose consisting in treating nitrocellulose with liquid nitroderivatives of ethylbenzene.

4. A process of colloiding nitrocellulose consisting in treating nitrocellulose with nitroderivatives of ethylbenzene.

5. A plastic composition including nitrocellulose colloided with a nitroderivative of ethylbenzene.

6. A plastic composition including nitrocellulose colloided with nitroderivatives of ethylbenzene.

7. An explosive consisting of nitrocellulose and a nitroderivative of ethylbenzene.

8. An explosive consisting of nitrocellulose and nitroderivatives of ethylbenzene.

9. The method of colloiding nitrocellulose consisting in treating it with not more than 27% trinitroethylbenzene.

GEORGE C. HALE.

not be usedin such high percent without a marked i 

